Fan Unit, Particularly for a Vacuum Cleaner

ABSTRACT

A vacuum cleaner fan with an electric drive motor having a stator assembly and a rotor. The stator assembly and rotor are disposed in a bearing pot. An at least single-stage fan unit is driven by the electric motor. The fan unit includes a guide stage, a suction cap, and an impeller that is configured to generate an air stream. The bearing pot includes a receiving pocket which holds an adapter housing. The adapter housing accommodates a printed circuit board. A power semiconductor operable to control rotational speed of the fan unit is included on the printed circuit board. At least a portion of the power semiconductor protrudes from the adapter housing into the vicinity of the air stream generated by the fan unit.

CROSS REFERENCE TO PRIOR APPLICATION

This is a U.S. National Phase application under 35 U.S.C. §371 of International Application No. PCT/EP2006/001643, filed Feb. 23, 2006 and claims the benefit of German Patent Application No. 10 2005 013 774.1, filed on Mar. 22, 2005. The International Application was published in German on Sep. 28, 2006 as WO 2006/099927 under PCT Article 21 (2).

FIELD OF THE INVENTION

The present invention relates to a vacuum cleaner fan, including an electric drive motor having a bearing pot for accommodating the component modules of the drive motor, such as a stator, rotor and, if present, brush holders with carbon brushes, and further including an at least single-stage fan unit which is driven by the motor and has a guide stage, an impeller, and a suction cap.

BACKGROUND

DE 199 51 861 A1 describes a vacuum cleaner fan with an adapter housing provided on the bearing pot. However, the portion of the adapter housing that projects into the air stream generated by the impeller is closed off. The aforementioned patent mentions, but does not elaborate on the possibility of mounting electrical power controllers on the printed circuit board.

Further, a similar fan unit is employed, for example, in a vacuum cleaner manufactured by the Applicant, namely the Miele S 712. The power semiconductor used therein is a Triac. In the Miele S 712, a control circuit board containing the Triac, a thermal switch, and a radio interference suppression capacitor, is screwed to the end face of the bearing pot which is opposite the impeller. In order to prevent overheating of the Triac, large-surface heat sinks are used to dissipate heat. These heat sinks are expensive and complicate assembly.

SUMMARY

It is, therefore, an aspect of the present invention to provide a vacuum cleaner fan in which optimum cooling is provided for the power semiconductor.

The invention provides a vacuum cleaner fan with an electric drive motor having a stator assembly and a rotor. The stator assembly and rotor are disposed in a bearing pot. An at least single-stage fan unit is driven by the electric motor. The fan unit includes a guide stage, a suction cap, and an impeller that is configured to generate an air stream. The bearing pot includes a receiving pocket which holds an adapter housing. The adapter housing accommodates a printed circuit board. A power semiconductor operable to control rotational speed of the fan unit is included on the printed circuit board. At least a portion of the power semiconductor protrudes from the adapter housing into the vicinity of the air stream generated by the fan unit.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be explained, based on exemplary embodiments, in more detail with reference to the following FIGS. 1-5, in which:

FIG. 1 is a longitudinal section through a fan unit designed in accordance with the present invention;

FIG. 2 is a perspective detail view showing the fan unit of FIG. 1 with the guide stage and with inserted adapter housing;

FIG. 3 is a detail of FIG. 2 in the region of the Triac;

FIG. 4 is a perspective front view showing the adapter housing and the control circuit board;

FIG. 5 is a perspective front view showing the adapter housing and the control circuit board with the cover removed.

DETAILED DESCRIPTION

The present invention provides for very efficient heat dissipation in spite of the fact that no heat sinks are used, by positioning the power semiconductor in the cooling air stream of the impeller.

In an embodiment of the invention, the adapter housing includes a lower part and a cover, the power semiconductor at least partially protruding through an opening formed in the cover. In such an arrangement, the other electrical and electronic components on the printed circuit board can be protected by the adapter housing. This facilitates handling during assembly and prevents destruction of these parts or of their solder connections on the printed circuit board. The power semiconductor may have a metallic flange which protrudes from the adapter housing. Via the flange, heat is efficiently removed from the power semiconductor, which ensures adequate cooling and allows the remainder of the power semiconductor to be protected by the adapter housing.

In order to facilitate assembly, the cover can be able to be snap-fitted to the lower part after insertion of the printed circuit board.

In an embodiment, the portion of the power semiconductor that projects into the air stream of the impeller is disposed behind an air supply opening of the guide stage. This is the location of greatest air flow. In addition, the air is cool since it has not yet passed any heated parts of the motor.

FIG. 1 shows a suction fan 1 for a vacuum cleaner, the assembly including an electric drive motor 2 and a fan unit 3 which is driven by the motor. Fan unit 3 is covered by a suction cap 4 which has an intake opening 5 for the suction air stream. A bearing pot 10 accommodates the known component modules of drive motor 2, such as wound stator assembly 6, rotor 7, and brush holders 8 with carbon brushes 9. Fan unit 3 is single-stage and includes a guide stage 11 located below suction cap 4, and an impeller 12. Guide stage 11 at the same time forms the bearing pot cover of drive motor 2, and is formed with a bearing seat 13 for receiving a bearing 13.1 for rotor shaft 7.1. The bearing 14.1 for the other end of rotor shaft 7.1 is disposed in a bearing seat 14 located in pot bottom 15 of bearing pot 10. In the example shown, bearing seat 14 is disposed in a cross-shaped bearing member 23 (see FIG. 2), which is formed in bearing pot bottom 15 and leaves open the air outlets 24 for the fan air which is passed through motor 2. The configuration in the form of a cross-shaped bearing member 23 is, of course, not mandatory. Instead, the suction air outlets may also be provided by any other pot bottom configuration, such as a closed pot bottom in combination with air slots formed in the side of the bearing pot.

Bearing pot 10, which is shown isolated in FIG. 2, is formed with a flange 16 on the side facing guide stage 11, said flange projecting beyond the pot. The edge projection 17 created in this manner has integrally formed first receiving pockets 18 which are open at the top and toward bearing pot 10 and in which the brush holders 8 of carbon brushes 9 can be inserted from above. When inserting brush holders 8, the terminal pins 21 of the brush holders are at the same time directly contacted into the stator assembly terminals 20, thereby establishing the electrically conductive connection between rotor 7 and the stator (see FIG. 1).

By forming bearing pot 10 with the edge projection 16, the electrical switching, control and/or safety features required for suction fan drive motor 2 can be implemented by disposing electrical components within bearing pot 10. These components are received in a further receiving pocket 27 which is open toward the interior of bearing pot 10.

The electrical components are mounted on a printed circuit board 29 (see FIG. 5), which is preferably also provided with terminal pins 30.1 and 30.2 for direct contacting to stator winding 6.1. As shown in FIGS. 4 and 5, printed circuit board 29 is inserted into a separate adapter housing 31, which in turn is inserted into receiving pocket 27. Receiving pocket 27 formed in bearing pot shell 19 is provided on the underside with a plug socket 32 for an external plug connector. Plug socket 32 penetrates shell 19 of bearing pot 10 in an axial direction. Adapter housing 31 containing printed circuit board 29 can be inserted into receiving pocket 27 in a form-fitting manner. The adapter housing is of a two-part construction, including a lower part 33 and a cover 34, which are connected together by snap-fit means 35.1 and 35.2 after insertion of printed circuit board 29.

Variation of the motor speed, and thus of the fan output, is accomplished by means of a phase control circuit in which a Triac 36 chops off portions of the line voltage half-waves supplied to the stator winding. This control method is generally known and is not described in greater detail here. Since the Triac 36 mounted on printed circuit board 29 is heated by the electric power supplied thereto, the present invention provides for the Triac to be disposed in the cooling air stream of impeller 12, said cooling air stream being denoted by the arrows in FIG. 1. For this purpose, cover 34 of adapter housing 31 is provided with an opening 37 through which protrudes metallic flange 38 of Triac 36. The position of receiving pocket 27 within bearing pot 10 and the dimensions of adapter housing 31 are matched in such a way that the flange 38 of Triac 36, which protrudes from housing cover 34, is located directly behind an air supply opening 39 in guide stage 11. Thus, the heat generated in Triac 36 is removed via the flange and by the air flowing through bearing pot 10. 

1-5. (canceled)
 6. A vacuum cleaner fan comprising: an electric drive motor having a stator assembly and a rotor; a bearing pot configured, to receive the stator assembly and the rotor; an at least single-stage fan unit configured to be driven by the electric drive motor and having a guide stage, an impeller, and a suction cap, the impeller configured to generate an air stream; a receiving pocket provided on the bearing pot; an adapter housing configured to receive a printed circuit board, the adapter housing being received in the receiving pocket; and a power semiconductor operable to control rotation speed of the at least single-stage fan unit, the power semiconductor being disposed on the printed circuit board, wherein at least a portion of the power semiconductor protrudes from the adapter housing in a region of the air stream.
 7. The vacuum cleaner fan recited in claim 6, wherein the electric drive motor comprises brush holders with carbon brushes, the bearing pot configured to receive the brush holders with the carbon brushes.
 8. The vacuum cleaner fan recited in claim 6, wherein the adapter housing includes a lower part and a cover having an opening, and wherein the portion of the power semiconductor protrudes through the opening.
 9. The vacuum cleaner fan recited in claim 6, wherein the portion of the power semiconductor includes a metallic flange.
 10. The vacuum cleaner fan recited in claim 8, wherein: the portion of the power semiconductor includes a metallic flange.
 11. The vacuum cleaner fan recited in claim 8, wherein the cover is snap-fittable on the lower part.
 12. The vacuum cleaner fan recited in claim 10, wherein the cover is snap-fittable on the lower part.
 13. The vacuum cleaner fan as recited in claim 6, wherein the portion of the power semiconductor is disposed in a vicinity of an air supply opening of the guide stage.
 14. The vacuum cleaner fan as recited in claim 8, wherein the portion of the power semiconductor is disposed in a vicinity of an air supply opening of the guide stage.
 15. The vacuum cleaner fan as recited in claim 9, wherein the portion of the power semiconductor is disposed in a vicinity of an air supply opening of the guide stage.
 16. The vacuum cleaner fan as recited in claim 11, wherein the portion of the power semiconductor is disposed in a vicinity of an air supply opening of the guide stage.
 17. The vacuum cleaner fan as recited in claim 12, wherein the portion of the power semiconductor is disposed in a vicinity of an air supply opening of the guide stage. 